Banff National Park, Canada. The Canadian Rockies reach their most dramatic proportions along the Icefields Parkway in Banff and Jasper National Parks. A collection of turquoise-hued glacial lakes provide sublime paddling beneath soaring glacier-draped mountains. These valleys were filled with enormous glaciers at the maximum extent of the ice sheets at the height of the Pleistocene Epoch about 20,000 years ago. The waters of this lake take on a cerulean hue in summer as the meltwater from glaciers along the crest of the Continental Divide flows into the lake with its burden of ground-up glacial silt. Suspended in the water of the lake, this milky solution absorbs the light at the short end of the visible-light spectrum causing the water to appear blue green.